I suffered from problem 1. I was able to steamroll my way through calculus II. Then I hit a brick wall in calculus III and came to the harsh realization that I

I suffered from problem 1. I was able to steamroll my way through calculus II. Then I hit a brick wall in calculus III and came to the harsh realization that I had simply rote memorized everything up to that point. I resolved to actually understand the material, so I took the rather drastic step of going through all of khan academy, starting with arithmetic, all the way through calculus. This was easier back in 2010, when all khan academy videos were on a single page. Luckily, the internet archive can help us out https://web.archive.org/web/20100206074742/http://www.khanacademy.org/ https://web.archive.org/web/20100206074742/http://www.khanac... By the time I finished, I had built up a good mathematical intuition. This was actually one of the most satisfying intellectual journies I have gone on. As a shout out to circa-2010 khan academy, it’s still so beautiful to me that all the videos are there, on one page. You can see them all, unlike the layout of the current website, where you can easily go down rabbit holes and lose your sense of progression.